1. Field of the Invention
The present invention relates to a method for controlling a storage system and to a storage control apparatus.
2. Description of the Related Art
In recent years, the environment surrounding information systems is rapidly changing such as the progress of information technology (IT) and measures for the shift to broadband. Along with this, the rapid increase of the amount of data handled is a serious problem in various occasions.
To deal with such an increase of the amount of data, storage systems operated in data centers are being subjected to larger capacities and higher performances of the storage control apparatuses such as disk array units. Therefore, for example, in data centers, introductions of and replacements with storage control apparatuses having higher performances and larger capacities are frequently carried out in order to respond to the rapid shift to larger capacities of storage control apparatuses.
There are methods for introducing a storage control apparatus, such as the ones in which the operation using the old storage control apparatuses has been completely shifted to the operation using only the newly introduced storage control apparatuses, and the ones in which the operation is carried out where the old storage control apparatuses coexist with the newly introduced storage control apparatuses.
As one of the former methods, there is a technology described in Japanese Patent Application Laid-open (Kokai) Publication No. Hei 10-508967. In this method, all the data can be operated by the new storage control apparatuses having a higher performance and a larger capacity, however, effective use of the old storage control apparatuses cannot be facilitated.
On the other hand, in one of the latter methods, the effective use of the old storage control apparatuses can be facilitated. However, the number of the storage control apparatuses directly connected to networks becomes necessarily increased because both of the new and the old storage control apparatuses coexist, and network structure information must be re-constructed because the new storage control apparatuses have been introduced to the existing networks. Therefore, an increase in management load imposed by the shift and the operation is inevitable.